College students Mimi and Cheolsu are friends, enjoying their students days together. Along the way, they make a new friend who calls himself Treasure Island and who amuses his fellow students with his unusual behavior.

College students Mimi and Cheolsu are friends, enjoying their students days together. Along the way, they make a new friend who calls himself Treasure Island and who amuses his fellow students with his unusual behavior. Mimi meets a medical student with a promising future and decides to get engaged to him. She tells Cheolsu that she and he should just be friends. That night, Cheolsu goes on a drinking binge to down his sorrows, accompanied by Treasure Island. Treasure Island collapses and has to be hospitalized. It's then that TI's secret comes out.